'Rez,
if you have,
Connected via cat5 cable to the dir-655 (same router I use btw),
Set a static IP on the dsm inside your network address space,
Tried to ping from another machine on the network or the router ping page and got nothing,
Have no connection to USB devices,
I think you're screwed.
Outside of taking off the cover and getting out a circuit analyzer, I can't think of anything you could do.
On the bright side, there are a lot of nice new boxes on the market...
chas